Peripheral nerve injuries often lead to incomplete recovery and contribute to significant disability to approximately 360,000 people in the USA each year. Stem cell therapy holds significant promise for peripheral nerve regeneration, but maintenance of stem cell viability and differentiation potential in vivo are still major obstacles for translation. Using a made-in-house 96-well vertical electrical stimulation (ES) platform, we investigated the effects of different stimulating pulse frequency, duration and field direction on human neural crest stem cell (NCSC) differentiation...

Nano α-MnO₂ is usually synthesized under hydrothermal conditions in acidic medium, which results in materials easily undergoing thermal reduction and offers single crystals often over 100 nm in size. In this study, α-MnO₂ built up of inter-grown ultra-small nanoflakes with 10 nm thickness was produced in a rapid two-step procedure starting via partial reduction in solution in basic medium subsequently followed by co-proportionation in thermal treatment. This approach offers phase-pure α-MnO₂ doped with potassium (cryptomelane type K0...

Herein, we demonstrate the fabrication of a three-dimensional (3D) polypyrrole-coated-porous graphene (PPy/PG) composite through in-situ polymerization of pyrrole monomer on PG surface. The PPy/PG displays a 3D hierarchical porous structure and the resulting PPy/PG hybrid serves as a conductive trap to lithium polysulfides enhancing the electrochemical performances. Owing to the superior conductivity and peculiar structure, a high initial discharge capacity of 1020 mAh g-1 and the reversible capacity of 802 mAh g-1 over 200 cycles are obtained for the S/PPy/PG cathode at 0...

6BaO·xCaO·2Al₂O₃ (x = 0.8, 1.2, 1.6, 2, and 2.2) aluminates were synthesized via a liquid phase co-precipitation method. Effects of the molar amount of CaO on the phase of aluminates before and after melting and their hygroscopic phase, melting properties, environmental stability, evaporation, and emission properties were systematically studied. The results show that with the increase of the molar amount of CaO, the aluminates change from a mixture phase to a single phase of Ba₃CaAl₂O₇, and the diffraction peak shifts to a higher angle...

The slow oxygen reduction reaction (ORR) hampers the efficiency of microbial fuel cells (MFCs) to a large extent, which usually requires catalysts to facilitate the electron transfer. The major challenge of the existed non-precious metals in place of the noble metal catalysts (Pt, Pd, Au et al.) for ORR is their low efficiency, which urgently needs special route to tackle this issue. Herein, we report a simple and convenient technique using prussian blue analogues as precursor to directly synthesize the N-doped graphene encapsulated CoFe alloy which is present in "Core-Shell" structure via calcination of Co2 Fe(CN)6 in inert condition...

Both light and a redox mediator riboflavin (RF) were utilized to promote the electro-oxidation of an NADH model compound (1-benzyl-1,4-dihydronicotinamide, BNAH), which is a key process for enzymatic biofuel cells to obtain a high performance. At the cathode, H+ ions were simultaneously reduced to produce H2 gas. To elucidate the cell reactions of this photogalvanic cell, which is significant information about the fabrication of enzymatic biofuel cells with a high performance, the effect of the BNAH and RF concentrations on the cell current, the light wavelength dependence on the current, and reduction of the RF concentration were evaluated...

Doping Ni-rich LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode material by small amount of Mo6+ ions, around 1 mol.%, affects pronouncedly its structure, surface properties, electronic and electrochemical behavior. Cathodes comprising Mo6+ doped NCM523 exhibited in Li cells higher specific capacities, higher rate capabilities, lower capacity fading and lower charge-transfer resistance that relates to a more stable electrode/solution interface due to doping. This, in turn, is ascribed to the fact that the Mo6+ ions tend to concentrate more at the surface, as a result of a synthesis that always includes a necessary calcination - high temperature stage...

As a significant constituent of lithium-sulfur batteries (LSBs), the separator also exerts a considerable effect on the performance of the sulfur cathode. In our work, the mixture of acetylene black and multi-walled carbon nanotubes is uniformly applied onto the commercial pp membranes to attain the modified separators. With investigaing different samples, the underlying influence of the coating layer is systematically scrutinized on the electrochemical behaviors of sulfur cathodes, relying on the extensive electrochemical and structural measurements...

This study investigated stimulation strategies to increase the selectivity of activating axonal pathways within the brain based on their orientations relative to clinical deep brain stimulation (DBS) lead implants.&#13; &#13; Approach: Previous work has shown how varying electrode shape and controlling the primary electric field direction through preclinical electrode arrays can produce orientation-selective axonal stimulation. Here, we significantly extend those results using computational models to evaluate the degree to which clinical DBS leads can direct stimulus-induced electric fields and generate orientation-selective activation of fiber pathways in the brain...

Out of many challenges in the realization of lithium-O2 batteries (LOB), the major is to deal with the instability of the electrolyte and the cathode interface under the stringent environment of both oxygen reduction and evolution reactions. Lithium nitrate was recently proposed as a promising salt for LOB, due to its capability to stabilize lithium anode by formation of solid electrolyte interphase (SEI), its low level of dissociation in aprotic solvents and its catalytic effect towards OER in rechargeable LOB...

Lithium metal anode is strongly regarded as a promising candidate in next-generation energy storage devices. Lithium nitrate (LiNO3) is widely applied as an effective additive in ether electrolyte to increase the interfacial stability in batteries with lithium metal anodes, however, LiNO3 is rarely involved in high-voltage-window carbonate electrolyte for its poor solubility. Herein, we realize the dissolution of LiNO3 in carbonate electrolyte through an effective solvation regulation strategy. LiNO3 can be directly dissolved in ethylene carbonate/diethyl carbonate electrolyte by adding trace amounts of copper fluoride as a dissolution promoter...

In this paper, the use of chemical local softness s(r) is proposed as an alternative way of analyzing the initial redox processes that occur in cathode materials used for lithium-ion batteries. It is shown that the chemical local softness is a quantity able to capture the same effects as the standard analysis based on the projected density of states. Because of its own nature, the local softness reveals the atomic sites involved in charge-transfer events and allows a quantitative comparative analysis between different materials...

Pulse electrochemically synthesis of a series of core-shell structured Ir@Pt/C catalysts in cathode catalysts layer are achieved to fabricate membrane electrode assemblies (MEA) with cathode ultra-low Pt loading. The single cell performance of the MEAs in a H2 /air PEMFC greatly rely on the sizes of the Ir core nanoparticle, and the optimum activity occurs with Ir core size of 4.1 nm. The cathode MEA with core-shell structured catalysts with optimal Ir core size exhibited excellent performance in a H2 /air single fuel cell, comparable to that of a commercial Pt/C MEA (Johnson Matthey 40% Pt), even though the Pt loading in Ir@Pt was only 40% that of the commercial Pt cathode (0...

Development of portable devices and electric vehicles calls for Li-ion batteries (LIBs) with higher energy density and better stability. Integration of FeF3 phases and carbon structures leads to promising cathode materials for LIBs with high voltage, capacity and power. In this study, FeF3·0.33H2O nanoparticles (NPs) were synthesized on reduced graphite oxide (rGO) nanosheets using an in situ approach. By chemically tuning the interfacial bonding between FeF3·0.33H2O and rGO, we successfully achieved high particle loading and enhanced cycling stability...

Freely deformable and free-standing electrodes together with high capacity are crucial to realizing flexible Li-ion batteries. Herein, a lamellar graphene/nanocellulose/silicon (GN/NC/Si) film assembled by interpenetrated graphene nanosheets is synthesized via a facile vacuum-assisted filtration approach accompanied by the covalent cross-linking effect of glutaraldehyde. The hybrid film consists of the highly conductive graphene matrix as an effective current collector, hydroxylated silicon nanoparticles (Si NPs) embedded uniformly within graphene interlayer and nanocellulose as adhesive to crosslink graphene and Si NPs...

Capacity decay has been a well-known phenomenon in battery technology. V6O13 has been proved to be one of promising cathode materials for the lithium-metal polymer battery owing to high electrochemical capacity and electronic conductivity. However, these V6O13-based cathodes suffer from characteristic capacity decline under operating conditions and it is also difficult to achieve the theoretical capacities of V6O13. Herein, we report, for the first time, the thermal instability between the components in the cathode composites using various analytical methods, such as in situ thermal gravimetric analysis - infrared spectroscopy, scanning electron microscopy and X-ray diffraction techniques...

High-energy lithium/sulfur (Li/S) batteries still suffer from unsatisfactory cycle life and poor rate-capability caused by the polysulfides shuttle and insulating nature of S cathodes. Here we report our findings in the controlled synthesis of selenium (Se)-containing S-rich copolymers of various compositions as novel cathode materials through a facile inverse vulcanization of S with selenium disulfide (SeS2) and 1,3-diisopropenylbenzene (DIB) as comonomers. Nuclear magnetic resonance and X-ray photoelectron spectroscopy results show that divinyl functional groups of DIB were chemically cross-linked with S/SeS2 chain radicals through a ring-opening polymerization...